Semiconductor electronic devices have internal losses which generate heat. When the electronic device is configured for a substantial amount of power, cooling is necessary in order to limit the semiconductor device to a sufficiently low temperature to provide a reasonable life.
It is conventional to remove heat from the dies of an electronic power module by hermetically enclosing the dies in a housing and then cooling the housing. Power modules containing this type of semiconductor component are traditionally attached to a cold plate. The cold plate may have fins thereon with circulation of fluid therepast. The fluid is usually liquid when greater amounts of heat must be dissipated. The heat has to travel from the die through the many layers of material before arriving at the cold plate or the housing case. The resistance to heat flow through each of the materials and interfaces causes the die to operate at a higher temperature or at a lower current level. It can be seen that, by reducing the material layers and interfaces between the coolant fluid and the heat-producing die, heat can be more readily extracted so that a die can carry higher current at the same junction temperature.